The Northeast Structural Genomics Consortium (NESG) is one of four Large-Scale Centers (LSCs) for structure production funded by the NIH NIGMS Protein Structure Initiative (PSI). The goals of the PSI LSCs are to (i) generate three-dimensional (3D) structures for large numbers of proteins selected using broad biological, genomic, and bioinformatics criteria, together with targets selected from specific biological theme projects, so as to provide significant structural coverage of a large number of protein sequences In nature, (ii) develop and disseminate novel and/or improved technologies for structural biology and bioinformatics, and (iii) make these structures, structure production data, and the associated reagents and technologies publicly available to the worldwide scientific community. In PSI:Biology, the next phase of the PSI program, the NESG will expand Its mission by carrying our collaborative structural genomics projects together with several PSI Consortia for High-Through-Put (HTP) Enabled Structural Biology Partnerships (Biology Partnerships) and associated Program Announcements (PARs). The primary goal of the NESG In PSI:Biology is to provide > 1,100 new 3D protein structures to the Protein Data Bank (PDB) over 5 years, together with extensive raw and processed data, protocols for sample production, structure/function annotations, and thousands of homology models derived from these structures. This will complement the ~ 900 structures deposited by NESG in PSI Phases 1 and 2. In particular, NESG will provide novel 3D structural information useful in modeling large numbers of eukaryotic and human proteins. Our efforts will span five classes of target types: (i) proteins nominated In collaborations to be established with PSI Biology Partnerships, (ii) domain families (referred to as BIG, MEGA, and META families) defined by the central PSI:Biology Target Selection Subcommittee to provide course-grained coverage of large protein domain families; (iii) proteins defined by the NESG Biomedical Theme of 'Networks of Proteins Associated with Human Cancer and Developmental Biology'; (iv) proteins nominated by the general biomedical research community, and (v) proteins selected for specific technology-development goals. Protein targets in the first two of these classes, representing ~ 80% of the overall NESG effort, will be selected in a coordinated process together with the other LSCs and Biology Partnerships so as to maximize biological impact and minimize redundant efforts. The many methods and technologies for structural genomics research developed in this project will provide the next- generation tools for traditional hypothesis-driven biological research, and will thus have powerful and broad impact on the infrastructure for biological science and engineering.